Telephone-receiver.



No. 687,997. Patenten 3, mol.

H. LIEBREICH.

TELEPHONE RECEIVER.

(Application led Nov. 30, 1900.)- (N 0 M Q d e l lll/,4,

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UNTTED STATES PATENT OFFICE.

.HANS LIEBREIOH, OF DETROIT, MICHIGAN.

TELEPHONE-RECEIVER.

SPECIFICATION forming part of Letters Patent No. 687,997, dated December 3, 1901.

Application iiled November 30, 1900. Serial No. 38,196. (No model.)

T0 all whom, it may concern Be itknown that I, HANS LIEBREICH, a citizen of the United States, residing at Detroit, in the county of IVayne and State of Michigan, have invented certain new and useful Improvements in Telephone-Receivers; and I do hereby declare the following to be a full,

clear, and exact description of the invention,-

such as will enable others skilled in the art to which it appertains to make and use the same.

Y My invention relates to improvements in telephonereceivers,and is particularly adapted for magnifying or intensifying the sound received over the line of a telephone apparatus.

It consists in a receiver provided With diaphragms, a series of permanent magnets interposed between them, some of the said magnets having coils around their poles, the said coils being connected with the telephone-line, and means for spacing the magnets apart, the structure being such that the magnets will produce a series of concentric vibrations upon the diaphragms.

It also consists in certain other novel constructions, combinations, and arrangements of parts, as will be hereinafter more fully described and specically claimed.

In the accompanying drawings, Figure l represents a vertical longitudinal section through a receiver embodying the present invention. Fig. 2 is a transverse section through the same and looking at the end of the magnets. Fig. 3 is a cross section through the receiver on the line of its spacing-block. Fig. 4 is a diagrammatic view of a telephone system, showing the manner of connecting the receiver with the same.

My improved receiver is so constructed as to transform the impulses received from the line-Wire and produce such vibrations of the diaphragms as to greatly increase the power of the sounds or impulses received and deliver them in a very audible condition. The

receiver is preferably formed with a cylin drical casing, as l, of suitable size and shape, and diaphragme 2 2 are secured to the ends thereof by means of cap-plates 3 3 of ordinary construction. The receiver preferably uses two diaphragme and is provided with a series of magnets 4 and 5. The magnet 4 is preferably located upon the central axis of the receiver and has its plus and minus poles arranged near the inner surfaces ofthe diaphragms at each end of the receiver. The ends of this magnet are preferably reduced, as at 6 6, and around the reduced end portions thus formed are secured coils 7 7. The coils are made of suitably-insulated wire and have a large number of windings, the said coils being connected with the line-Wires 8 8 of the telephone system.

Around the central magnet 4 are arranged a series of magnets 5 5, which are held in place by a central spacing-block 9, secured in position in the casing l and also holding the magnet 4 in position. The magnets 4 and 5 are preferably permanent magnets, and the magnets 5 5 are preferably arranged with their minus poles at the same end of the receiver that contains the plus pole of the magnet 4, the plus poles of the magnet 5 being arranged near the minus pole of the center magnet. By this structure the magnetic currents pass from the magnets 5 over the diaphragm to the center magnet 4. The ends of the magnets 5 are also arranged close to the inner surfaces ofthe diaphragm 2 2 and be ing free at their ends to vibrate are altered in their positions beneath the diaphragms by the action of the coils at the ends of the permanent magnet 4. The diaphragms Will thus be drawn into a series of concentric Waves or vibrations by the action of the magnets 4 and 5. The central spacing-block 9 is also provided With a series of apertures 10 10, so that the air in one end of the receiver may pass freely to the other end thereof, according to the action of the diaphragms. This arrangement results in the diaphragme acting in unison with each other and so connects them as to greatly increase the power of their transmission. The diaphragms are polarized, so as to be capable of such action.

A receiver of this kind can be used upon ordinary telephone-lines, but is much more effective when employed upon a line using a transformer for increasing the efficiency of the same. YVhen used with such a transformer, the instrument is exceedingly sensitive and results are produced which far exceed the ordinary telephones in use and even the microphones as now made.

IOO

tu E" In constructing the central magnet'its sensitiveness to theimpulses received by the coils 7 7 may be increased as desired by slitting the reduced ends 6 6 thereof by a slot extending from the periphery of each reduced end to its central' axis. It will be apparent that other minor changes may be made in the structure of the receiver Without departing in the least from the present invention. l

I find in use that a receiver of this kind isadmirably adapted for increasing the efficiency of telephone instruments, that lvery slight sounds or impulses can be reproduced at a distance with great clearness, and that sounds can be heard immediately at the receiver or at a distance therefrom.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is-

l. A telephone-receiver comprising a casing, diaphragms mounted therein, a core interposed between said diaphragms and adapted to act upon the same comprising a series of permanent magnets mounted in concentric circles Within the casing, the ends of the said magnets coming close to the diaphragms so as to act directly upon the same, coils sur rounding the poles of one of the magnets, the said coils being connected with the telephone-line, the structure being such that the diaphragms will be vibrated in vaccordance with the impulses received from the linejwire by the said coils, substantially as described.

2. A telephone-receiver 'having a series of diaphragms, acore for acting upon the same comprising a central magnet and a series of magnets arranged around the same, all being interposed between the diaphragms, the ends of all of them extending into close proximity to the said diaphragms, coils surrounding the poles of the central magnet and connected with the telephone-line, the structure being such that all of the magnets will be in position to act directly upon the diaphragme,

the said diaphragms being attracted at their centers and in one or more concentric circles, substantially as described.

3. A telephone-receiver comprising a casing, diaphragms secured at each end of the casing, a core interposed between the diaphragms made up of a central magnet, and a series of magnets arranged around the same and spaced a suitable distance therefrom, reduced end portions formed upon the ends of the central magnet, coils of wire Wound about the said reduced end portions and connected with the telephone-line, a spacing-block for holding the magnets in the casing at a point intermediate of their length, said block having a series of apertures formed therein for permitting the column of air between the diaphragms to move back and forth in the receiver, whereby the vibrations of the said diaphragms are unified and their effect increased, substantially as described.

4. A receiver for telephones comprising a casing, diaphragms mounted therein, a core arranged so that its ends approach the diaphragms, a central magnet 'forming a part of said core having reduced slotted end portions, coils surrounding the said reduced ends and connected with a telephone-line, the remaining magnets of the said core being arranged in a concentric circle around the central magnet, a spacing-block for holding the magnets a proper distance from each other 

